Method of making wound bobbins



Nov. 9, 1937. D. e. BAKER METHOD OF MAKING WOUND BOBBINS Filed April 13, 1935 INVENTOR Dwlrerson G. Baker A ORNEYS Patented Nov. 9, 1937 PATENT OFFICE 2,098,219 v METHOD OF MAKING WOUND BOBBINS Dickerson G. Baker, Holyoke, Mass., assignor to The American Thread Company, New York, N. Y., a corporation of New Jersey Application April 13, 1935, Serial No. 16,148

1 Claim.

My invention relates to a method of making bobbins and has special reference to a method of making'bobbins for sewing machine shuttles of the type of the one described and claimed in 5 the patent to Snyder and Curry, No. 1,481,243,

dated January 15, 1924.

Shuttle bobbins of the type indicated are usually about three quarters of an inch in diameter and the core of the bobbin is about five-sixteenths of an inch in diameter. The thread is cross wound on the core, and when completely wound, the ends of the core project only a slight distance, somewhat less than one-sixteenth of an inch, from the ends of the mass of thread. The wound core is placed in dies with the end disks positioned over the ends of the core. Then the mass of thread, disks and core are axially compressed, and the projecting ends of the core are swaged over the outer sides of the disks so as to firmly hold the disks against the ends of the thread mass. With this type of bobbin, considerable difliculty has heretofore been experienced in one or the other of the swaged ends of the core not securely holding the associated disk in place. I

have found that this difliculty has been owing to the fact that as the ends of the core project only a slight distance, as above-mentioned, beyond the ends of the mass of thread, if the thread mass is shifted slightly on the core during the pressing operation or the disks are unevenly applied, one end of the core may not project sumciently beyond its associated disk to enable it to be efiec-- tively swaged against the disk.

One of the objects of the present invention is to provide a method to insure that when the disks have been applied and the disks, thread mass and core are compressed that the ends of the core of each bobbin will project uniform distances from the ends of the associated disks, thus insuring adequate length of both of the projecting ends of the core to effect proper swaging of the ends.

The improvement will be more clearly understood from the following description and accompanying drawing in which:

Figure 1 is a view in perspective of my improved bobbin in its preferred form; I

Fig. 2 is a longitudinal sectional view of the bobbin; Fig. 3 is a detail view in perspective of the core of the bobbin; and

Figs. 4, 5, 6 and '7 are longitudinal sectional views of cores of modified forms.

The bobbin illustrated in Figs. 1 and 2 of the to drawing is provided with a tubular core 2 on (Cl. 112-251) Y which is cross wound a mass of thread 4. Fitted on the ends of the core in close contact with the ends of the thread mass are annular disks 6 preferably of resilient paper. The disks are held against the mass by means of the ends of the core 5 which are swaged over the outer sides of the disks.

In accordance with the present invention the core is provided with annular shoulders 8 which are spaced equal distances from the ends of the 0 core. The thread is wound on this core substantially flush with the shoulders 8. Y After the thread is thus wound on the core, the disks 6 are placed on the ends of the core and against the thread mass, the openings in the disks being sub- 5 stantially the same diameter as the diameter of the ends of the core so as to provide a tight flt between the disks and core. The mass of thread, disks and coreare then axially compressed by means of suitable dies, and the projecting ends of so the coreare swaged over to hold the disks in place.

The provision of the shoulders 8 insures that both ends of the core will project from the disks a suflicient distance to allow for proper swaging 25 of the ends of the core over the outer sides of the disks, and overcomes the danger of the thread 'mass shifting on the core during the compressing operation. In addition to the shoulders thus serving to limit the inward movement of the 30 disks, they together with the swaged ends of the core securely clamp the disks in position, so that there is no danger of the disks tipping or -otherwise moving inwardiy dining the unwinding of the thread.

The shoulders 8 may be formed by means of outwardly projecting annular beads l0 pressed in the core (Figs. 2 and 3). The core inthis form may be of sheet metal. If desired, however, the shoulders may be formed by reducing the 0 ends l2 of the core as shown in Fig. 4. Another way of forming the shoulders is to provide two tubes l4 and it which may be of paper. with the tube ll extending through the tube l6 and the ends of the inner tube It projecting uniform dis- 45 tances from the ends of the tube Hi. the ends of the tube 16 forming the shoulders. The tubes I4 and I6 are in tight fitting engagement so as to secure them together or they may be otherwise secured.

If desired the core may be formed of thin sheet metal or other suitable material, as shown in Fig. 6, which is shaped to form the shoulders It.

The form shown in Fig. '7 is similar to the form shown in Fig. 6, except that the peripheral sur- What I claim is:

The method of making bobbins of the type described which comprises cross winding thread on a core having shoulders spaced equal distances from the ends of the core, the thread being wound substantially flush with the shoulders on the core, thereafter applying disks on the ends of the core, subjecting the disks, mass of thread and core to pressure axially applied, and swaging over the ends of the core so as to cause said ends to hold the disks against said shoulders an against the thread mass.

DICKERSQN G. BAKER. 

